The present invention relates to manufacturing articles molded out of plastics material, and more particularly, but not exclusively, to manufacturing devices for packaging cosmetics.
French patent 2 413 205 and European patent 0 438 339 in the name of the Applicant company disclose methods of manufacturing articles of molded plastics material that make it possible to imitate the appearance of stone, of marble, or of mother-of-pearl.
Those methods make it possible, in particular, to improve the appearance of devices for packaging cosmetics.
Nevertheless, there exists a need to create novel optical effects so as to make such devices even more attractive to the consumer.
In addition, known methods do not give complete satisfaction since marking can be observed on the surface of certain articles due to the flow of the material during molding, and that detracts from the appearance thereof.
An object of the present invention is to remedy that drawback and to make packaging devices, particularly for cosmetics, even more attractive to the consumer.
The invention achieves this by an article made of molded plastics material, said article comprising a matrix of transparent plastics material incorporating a filler constituted essentially by fibers, said filler constituting 1% to 25% by mass, and the mean length of the fibers constituting said filler lying in the range 100 xcexcm to 700 xcexcm. Preferably, the filler constituteand 1% to 15% by mass, advantageously 2% to 10%, and the mean length of the fibers preferably lies in the range 150 xcexcm to 550 xcexcm.
The proportions given above correspond to filler mass relative to total mass of filler plus transparent plastics material.
Also preferably, the filler is constituted by vegetable fibers, advantageously wood fibers, which fibers may be colored or made reflective by being encapsulated in colored or reflecting material.
In the meaning of the present invention, the term xe2x80x9cfiberxe2x80x9d should be understood as covering any generally oblong body of outline that is preferably irregular.
The plastics material used may be colored while nevertheless remaining transparent.
Opalescent effects may be created by acting on the surface state of the article, i.e. by giving parts of its surface a satin finish.
When the surface of the article is polished, it is also possible to create a magnifying glass effect.
The article can be shaped using any known method of molding thermoplastics material, such as injection molding, for example.
In general, the wall thickness of an article molded in accordance with the invention is at least 0.2 mm, and is preferably greater than or equal to 1 mm.
The invention also provides a method of manufacturing an article of molded plastics material as specified above, the method comprising the steps consisting in:
mixing a transparent plastics material with a filler that is essentially constituted by fibers, the filler constituting 1% to 25% by mass of the mixture and the mean length of the fibers lying in the range 100 xcexcm to 700 xcexcm; and
molding the article.
The invention also provides a composition for molding, wherein the composition is essentially, or exclusively, constituted by a mixture of a transparent plastics material and a fiber filler, the filler constituting 1% to 25% by mass of the mixture, and said fibers constituting said filler having a mean length lying in the range 100 xcexcm to 700 xcexcm.
As the transparent plastics material, it is possible to use a thermoplastics material such as a styrene, e.g. polystyrene (PS), a polyolephin such as transparent poly-propylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), a polyacrylic (PMMA), or a copolymer such as, for example, styrene/acrylonitrile (SAN), said list naturally not being limiting.
It is also possible to use a mixture of transparent thermoplastics materials of different chemical natures.